We have several Norway Spruce trees that were planted approximately 4.5 years ago. They were all around 5-6′ at the time of planting and had root balls. They were mulched immediately after planting. After about 2 years, the bottom half of the trees started thinning out dramatically. It at first started with just one tree but has now spread to about 7 out of the 10 trees that we’ve planted. They all came from the same nursery. Could you tell us what would be causing the bottom half only to die off? They tops are still growing and pine cones still form on all of them. I have pictures as well that I could send or attach. We’re afraid that we’ll have to get rid of most or all of them. They are planted in Bracken County in very clayey soil. Thank you for your time!
The Gardener’s Answer
Hi, Elizabeth: All plants are more susceptible to insect and disease problems when the growing conditions are not ideal. Norway Spruce (Picea abies) prefer to grow in acidic and moist but well-drained soil. A minimum of six hours of direct sunlight is best.
I can’t be certain what is going on with your evergreens but from the picture that you sent it almost looks like deer damage but from the way you described the progression, your spruce may have a fungal disease known as Cytospora Canker. You will want to have someone look at it in person and under a lens to be certain. You can have a certified arborist come out or you can take a sample to your County Cooperative Extension Service. The horticulture agent will be able to give you a positive diagnosis and treatment options. The Bracken County offices are located at 1120 Brooksville-Germantown Road. The phone is (606) 735-2141.
For now you will want to make sure that the stakes are not too tightly attached to the tree. This can cause girdling and prevent the tree from moving nutrients throughout. Cultural practices are just as important in growing healthy trees. You may want to consider increasing the mulched ring around the base of the tree. It should extend out as far as the longest branches. Remove all fallen debris and weeds around the trees as this is a great way to spread disease. Apply a 3-4 inch layer of mulch but be sure that it is not piled up around the tree trunks. I hope this is helpful.